The Drawing of the Dark is Tim Powers's first foray into the world of the mysterious Fisher King. The book is set in the 1500's, during a war (that actually did happen) in Austria. The main character Brian Duffy, is a swordsman of amazing skill, and has the reincarnated spirit of King Arthur living inside him.
As Powers books go, this one is pretty short, but not at all a bad read. You'll find the title itself is particularly clever, once you've read the book.